This proposal will allow the Principal Investigator (PI) to develop as an independent investigator with a novel focus on emergency department (ED) screening and surveillance of HIV infection, and factors related to HIV infection. The ED represents a new frontier for public health intervention, presenting opportunities to monitor infectious diseases of public health importance, to increase penetration of at-risk populations with screening and intervention programs, and to reduce health disparities. Maximizing these opportunities requires trained clinical researchers. The PI, an Assistant Professor of Emergency Medicine, will complete a Masters in Public Health and advanced epidemiology and biostatistics courses as part of an individualized curriculum designed by his mentors. Research projects will allow for practical experience, application of knowledge gained, and generation of preliminary data for future NIH funding. Specific aims are: 1) to develop skills in clinical research methodology, epidemiology, and biostatistics to become an independent and fully funded clinical researcher;2) to evaluate HIV screening in an urban ED in a city with low HIV seroprevalence (<1%) by comparing a targeted HIV screening strategy (testing offered to those perceived to be at-risk) to: a) concurrently obtained ED seroprevalence estimates, b) routine screening (testing offered to all regardless of risk), and c) targeted screening in community health centers. These aims are complementary to the career development of the PI and provide a unique opportunity to positively impact the HIV epidemic. The PI will attain the skills of a clinical researcher under the direct supervision of a multi-disciplinary group of highly qualified mentors. His prior research experience demonstrates a dedication to ED-based HIV prevention research and the ability to coordinate multi-disciplinary collaboration. By capitalizing on current collaborative and mentoring relationships as well as institutional strengths, the PI will develop an evidence- based public health program that can reach a population that is notoriously difficult to penetrate. The quintessential contribution of this research will be to not only help mitigate the HIV epidemic, but to provide evidence for the utility of ED-based screening and surveillance for infectious diseases of national public health importance.